springer



F. W. SPRINGER.

LIQUID FUEL FEED SYSTEM FOR GAS ENGINES.

AP ILICAIION FILED I'EB. I3, I820.

' Patented June 6, 1922..

2 SHEETS-SHEET I.

; INVENTOR- FRA/wru/v W SPR/N BY 7/; ma

A TTORNE YSI F. W. SPRINGER.

LIQUID FUEL FEED SYSTEM FOR GAS ENGINES.

APPLICA'I- ON FILED FEB. 13, I920.

Patented June 6, 1922.

2 SHEETS-SHEET 2.

INVENTOA: FRA/v/ru/v WSPR/N ER. BY 0;!

ATTORNEXS.

UNITED STATES FRANKLIN W. SPRINGER, OF MINNEALPOLIS MINNESOTA.

LIQUID-FUEL-FEED SYSTEM FOR GAS ENGINES.

Specification of Letters Patent. t t J 6 192% Application filed February 13, 19 20. Serial No. 358,331. a

To all whom it may cancer-n:

' Be it known that I, FRANKLIN WV. SPRINGER, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Liquid Fuel-Feed Systems for Gas Engines, of which the following is a specification. 9

My invent-ion relates primarily to liquid fuel feed systems for gas engines. Anobject is to provide a device for maintaining a constant suction (or pressure) head for liquid fuel tanks and thus avoid the use of fioat-' feed carburetors with their well-known fire risks, due to flooding. Another object of my invention is to provide a safety device which will prevent flooding due to expansion of the liquid fuel when the tank is filled with the same when cold. In the use of my device the liquid fuel as it enters the feed pipe leading to the carburetor is under substantially the same pressure regardless of the quantity contained in the tank. An instance in which my device may be employed to advantage is in connection with farm lighting plants employing a gas engine to operate an electric generator. When my construction is employed the liquid fuel goes into the feed pipe under substantially the same pressure at all times and there is no necessity for changin the ca'rbureter adjustment according to the quantity of liquid fuel in the supply tank, thus enabling the engine to be run without attention to carbureter adjustment.

The full objects and advantages of my invention will appear in connection with the detailed description thereof and the novel features embodied in my inventive idea-will be particularly pointed out in the claims.

In the accompanying drawings, which illustrate the application of my invention in several different forms,-

Fig. 1 is a "iew in vertical longitudinal section of one form of my device. Fig. 2 is a similar view of another form. Fig. 3 is a similar view of another form. Fig. 4 is a similar view of another form. Fig. 5 is a similar view of another form and Fig. 6 is a similar view of another form. v

In the embodiment shown in Fig. 1, the numeral 10 designates aclosed tank or supply reservoir from which a feed pipe 12 leads to a carburetor. T he pipe 12 terminates adjacent the bottom of the tank and 1 s sufliciently spaced therefrom so that liquid fuel in the tank may be readily drawn into the pipe by suction from the engine. An air nlet-pipe 14 extends from the outside down into the tank and the lower end of this tube, Wl11Ch 1 S contracted at 16 to prevent surging, 1s pos tloned somewhat above the lower end of the,feed pipe 12. It is evident that-as liquid fuel is drawn from the tank there -Will be a constant working level indicated at a for the suction (or pressure) head. This constant working level will be maintained regardless of the amount of liquid fuel. in the tank as long as there is sufficient liquid fuel to cover the lower end of the air inlet ube 14. A suitable form of safety device is shown in this figure constructed as follows. A receptacle 18 having an opening 19 and adapted to contain a suitable liquid'such as mercury or oil is positioned upon the tanklO'. Aninverted U-tube 20 has one end extending into the receptacle 18 and its other end extending into the top of thetank 10. When the tank is filled with liquid fuel which is cold, this fuel as it expands and volatilizes, due' to increase in temperature, will cause the liquid to rise in the tubes 12 and 14 with a tendency .to overflow outside of the tank. But when the safety device is employed, the left-hand portion of the tube 20 takes up the gas pressure. In order for this device to operate successfully it is obvious that the height of the tube 20 must be such that the column of mercury or other liquid in the right-hand portion of the tube 20 will stand the pull of the full head and the height of thetube 14 must be such that the pressure head 'of'the fuel therein will be greater than the pressure head of the mercury in the receptacle '18. -A cock 22 may also be provided to prevent overflow or flooding, this cock being'closed when the engine is running but being open at other times. This cock may be connectedwith any suitable overflow receptacle such as that described in connection with Fig. 2.

Fig. 2 illustrates another form of construction in which the tank 24 is provided with a feed pipe 26 which leads to the carburetor. An air inlet tube 28 extending into the tank has its lower contracted end30 located above the lower end of the feedplpe 26 to provide a constant working level indicated at b. A cock 22 similar to that already referred to is provided, and this is shown connected by a tube 31 with an overflow receptacle 33, a vent hole 35 being provided where the tube leads into the receptacle. Fig. 3 shows an embodiment of my invention in which a tank 32 is provided with a feed pipe 3% and with an air tube 36 which is adjacent the pipe 34 instead of extending down through the filling opening as shown in Figs. 1 and 2. The constant working level is indicated at c. In Fig. 4 a tank 38 is provided with a feed pipe 40 extending through the bottom thereof. An air tube 42 extends into the tank, the lower end of this tube determining the working level at (I. In

Fig. 5 a tank 44 is connectedto a receptacle 46 adjacent thereto by a tube -18 having a down-turned contracted end 50 which terminates near the bottom of the receptacle 46 but somewhat above the lower end of a feed pipe 5:? leading to the carburetor. The top of the receptacle 46 is provided with a vent hole 54 and therefore a constant working level is provided adjacent the lower end of the tube -18. as indicated at c. The receptacle 46 serves to receive the overflow as the temperature rises after the tank 4:4 has been filled with cold liquid fuel and in casecock 2:2 is not used as indicated. Fig. 6 shows a tank 56 having a feed pipe 58 the lower end of which terminates above a plug 60 in the bottom of the tank. An air tube 62 has one. end terminating near the bottom of the tank 56, and this pipe after passing above the tank and being extended in a horizontal position with a vent opening 63, has its other end passed for a short distance through a cork 64 in the neck of a receptacle 66. This receptacle when the clock 22 is not used serves to receive any. overflow ofliquid fuel due to rise in temperature, and since it is not attached to the tank 56, the overflow may be poured back into the tank at the time of next lling. The working le vel is determined by the lower end of the tube 62 and is indicated at f.

The operation and advantages of my invention will be obvious from the foregoing description. \Vhen the engine is started liquid fuel will be drawn out of the tank through the feed pipe and a vacuum will start to form at the top of the tank. The volume of the air inlet tubes 14, 28, 36, 42, 50 and 62 being small. the tank assumesthe working pressure. level indicated at a to f almost immediately upon starting the engine so that there is no change in fuel flow to the carburetor.

I claim 1. A liquid fuel feed system for gas engines comprising a supply tank, a feed pipe for conducting the fuel from said tank to the engine, means for maintaining a constant pressure head in said tank, and means for preventing flooding when the temperature of the fuel rises.

2. A liquid fuel feed system for gas engines comprising a supply tank, a feed pipe for conducting the fuel from said tank to the engine, means for maintaining a constant pressure head in said tank, and means external to said tank for preventing flooding when the temperatureof the fuel rises.

3. A liquid fuel feed system for gas engines comprising a supply tank. a suction pipe for conducting the fuel from said tank to the engine. means for maintaining a constant suction head for said suction pipe. and means for preventing flooding when the temperature of thefuel rises.

l. A liquid fuel feed system for gas engines comprising a supply tank. a suction pipe for conducting the fuel from said tank to the engine. means for maintaining a constant suction head for said suction pipe, and means external to said tank for preventing flooding when the temperature of the fuel rises.

5. A liquid fuel feed system for gas engines comprising a supply tank, a feed pipe for conducting the fuel from said tank to the engine. means substantially immediately responsive to starting of the engine for maintaining a constant pressure head in said tank, and means for preventing. flooding when the temperature of the fuel rises.

6. A liquid fuel feed system for gas engines comprising a supply tank. a feed pipe for conducting the fuel from said tank to the engine, means substantially immediately responsive to starting of the engine for maintaining a constant pressure head in said tank, and means external to said tank for preventing flooding when the temperature of the fuel rises.

7. A liquid fuel feed system for gas engines comprising a closed tank, a feed pipe for conducting the fuel from' said tank to the engine, an air-inlettube for said tank, the lower end of said tube being located slightly above the inlet end of said {pipe whereby a constant working level is maintained. and means connected with said tank to prevent the escape of liquid fuel upon expansion thereof resulting from rise. in temperature. 8. A liquid fuel feed system for gas engines comprising a closed tank, a feed pipe for conducting the fuel from said tank to the engine, an air-inlet tube for said tank, the lower end of said tube being located slightly above the inlet end of said pipe whereby a constant working level is maintained, and a container connected with said tank for receiving overflow of liquid fuel upon expansion thereof resulting from rise in temperature.

9. A liquid fuel feed system for gas engmes comprising a closed tank, a feed pipe extending into said tank and terminating close to the bottom thereof. an air-inlet tube extending into said tank, the lower end of said tube being located slightly above the mlct end of said feed pipe whereby a constant working level is maintained, and a container connected with said tank for receiving overflow of liquid fuel upon expansion thereof resulting from rise in temperaturel 10. A liquid fuel feed system for gas engines comprising a closedtank, a feed pipe for conducting the fuel from said tank to the engine. an air-inlet tube for said tank,

a receptacle mounted exterior to said tank, and an inverted U-tube having its ends extending into said tank and into said receptacle respectively, the height of said airinlet tube being such that the pressure head of fuel therein will be greater than the pressure head of liquid contained in said receptacle.

11. A liquid fuel feed system for gas engines comprising a closed tank, a feed pipe for conducting the fuel from said tank to the engine. and an air inlet tube for said tank. the lower end of said tube being located slightly above the inlet end of said feed pipe whereby a constant suction head is maintained in said tank and said lower end being Contracted to prevent surging.

In testimony whereof I hereunto atlix Ill) signature.

FRANKLIN \V. SPRINGER. 

